Method of rendering misuse of communication services more difficult

ABSTRACT

In many communication service, such as for example virtual card calling (VCC), authentication methods are used to check the access authorization of the caller to the communication service, and thus to prevent possible misuse. A chance-controlled fee assessment is used to prevent possible misuse of the communication service.

BACKGROUND OF THE INVENTION

For many communication services, realized for example with the aid of aintelligent network (IN), such as for example Virtual Card Calling(VCC), Universal Personal Telecommunication (UPT), remote access toVirtual Private Network (VPN) and multimedia services, authenticationmethods are used to check the caller's access authorization to thecommunication service and to allocate the fees to him.

Such authentication methods are usually based on the input of a useridentification (e.g., a card number) and, if warranted, a personalidentification number (PIN) as well. The user must keep theseauthentication data secret.

The foregoing authentication methods can offer only limited security.This is because valid authentication data can in principle be determinedby trying out a large number of data, and can then be used abusively,e.g. in order to carry out communications at the expense of someoneelse.

If this misuse (illegal use) is to be impeded by the use of numbers witha larger number of digits, acceptance problems arise, since very longinputs are then necessary in normal use (legal use).

An impedance of misuse can also be effected in principle by chargingfees for unsuccessful authentication processes. However, this chargingof fees cannot take place to the account of the user, as actuallydesired, because at the time of unsuccessful authentication processesthe user has not yet been identified. In place of this, a charge to theaccount of the terminal used is on the other hand undesirable for thelegal use of these services, because it contradicts the fee principle ofthese services. This is because according to this fee principle, theterminal used should remain free of fees, because the terminal used inthese services may belong to a third party.

The result of the above is that, under the control at a PC, thousands ofauthentication attempts can be carried out abusively (with a chance ofsuccess) without any fees thereby arising for the abusive caller(illegal user). The misuse can thus be practiced commercially.

Due to the circumstance that unsuccessful authentication processes arefree of charge, a further case of misuse is also made easier. Forreasons of security, access to a service is as a standard procedureblocked for a user if, given his identification, a predetermined numberof false PIN entries is exceeded. Persons with malicious intent can makeuse of this to block access to services for others deliberately andwithout incurring fees.

SUMMARY OF THE INVENTION

The invention is based on the object of impeding the named misuse,without thereby having any significant adverse effect on the legal useof the services named.

In general terms the present invention is a method for impeding misusein communication services, in which user-specific authentication datamust be inputted in order to call a communication service. Theauthentication of the service user is carried out by the communicationnetwork. A chance-controlled fee assessment is caused for the networkterminal used to call the communication service, before the service usercan determine that there has been an unsuccessful authentication.

The present invention is also an authentication means of a network,which, given a call to a communication service by a user, carries out anauthentication by checking the authentication data indicated by theuser. Given successful authentication, the user gains access to thecommunication service. The authentication causes a chance-controlled feeassessment for the network terminal used to carry out the call, beforethe service user can determine that there has been an unsuccessfulauthentication.

By means of the invention, the following is achieved:

In case of input errors, the normal user can expect that there is only arelatively low probability (e.g. 1:20 chance) that the terminal he isusing will be charging a fee.

In contrast, in the case of misuse there necessarily occurs a highnumber of failed attempts while the possibilities are being sequentiallytried. If, due to the statistical degree of security, an average of e.g.10,000 failed attempts are necessary in order to find a successfulauthentication by chance, and a probability of a charge of for exampleone in twenty is predetermined, then on average 500 attempts will bepaid. The misuse can thereby become economically not worthwhile,especially if relatively low credit limits are established for theaccounts that are determined to be subject to abuse. At higher creditlimits, either the statistical degree of security can be increased, orthe probability of a charge can be increased.

BRIEF DESCRIPTION OF THE DRAWING

The features of the present invention which are believed to be novel,are set forth with particularity in the appended claims. The invention,together with further objects and advantages, may best be understood byreference to the following description, in which:

The single FIGURE depicts an embodiment of the present invention and useof the method of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, an exemplary embodiment of the invention is explainedin more detail on the basis of the procedure that takes place in a call(see the single FIGURE).

A call to one of the services mentioned above is first begun free offees. If the service controlling SCP in an intelligent network INrecognizes an unsuccessful authentication attempt, (authenticationchecker AC) it determines in a manner controlled by chance whether acharge should take place for the terminal used by the caller.

If the chance controlling yields a positive result, it gives a fee orderto the charging, e.g. an exchange EX in the network IN. The chargethereby becomes effective before the caller learns the result of theauthentication check. A particular probability is predetermined for thechance controlling, for example, a 1:20 chance.

The following is thereby achieved:

In case of input errors, the normal user can expect that there is only arelatively low probability (e.g. 1:20) that the terminal he is usingwill be charged a fee.

In contrast, in the case of misuse there necessarily occurs a highnumber of failed attempts while the possibilities are being sequentiallytried. If, due to the statistical degree of security, an average of e.g.10,000 failed attempts are necessary in order to find a successfulauthentication by chance, and a probability of fee charge of e.g. 1:20is predetermined, then on average 500 attempts will be paid. The misusecan thereby become economically not worthwhile, especially if relativelylow credit limits are established for the abusively determined accounts.At higher credit limits, either the statistical degree of security canbe increased, or the probability of a charge can be increased.

The probability to be predetermined for the chance controlling can beadapted on the one hand to the existing statistical degree of securityand on the other hand to the expected user acceptance for the changesfor of failed attempts.

This relatively simple method for impeding misuse by means ofchance-controlled charges of unsuccessful authentication attempts is initself particularly suitable when the existing statistical degree ofsecurity is relatively high, due to a larger number of digits for useridentification and/or PIN, so that in the case of misuse a very largenumber of authentication attempts is required.

In the following, a further method for impeding misuse is explained inmore detail, offering specific advantages (to be explained later) inconnection with the previous method.

For the realization of this further method, the charging means FA, whichis for example realized in an exchange EX in the network IN, is equippedso that it can carry out a provisional charge that can be canceled. Thisspecial charge becomes effective when a call is terminated, before acancellation of the charge has taken place.

The sequence of the method is as follows:

If, given a call to a relevant service, the service controlling SCP hasrecognized a complete but unsuccessful authentication, then it assignsthe activation of the provisional, cancellable charge to the exchange EXto which the terminal TR of the call is allocated. (The activation canin principle also take place immediately at the beginning of the call.However, this is less favorable with respect to acceptance, because thenpremature interruptions become subject to fees.)

The activation is thereupon carried out by the exchange EX to which ithas been assigned, before the caller learns the result of theauthentication test. (In this way, it is ensured that the misuser cannotcarry out any single attempts without incurring a fee.)

If the service controlling subsequently recognizes a successfulauthentication, it gives the order for the cancellation of the charge,and the overall authentication process remains free of charge.

However, if a call is terminated after an unsuccessful authentication,without a subsequent successful authentication leading to a cancellationof the provisional fee assessment, a fee is charged for the call.

The permissible number of unsuccessful authentications within a call islimited, e.g. to three. If this is exceeded, the call is charged a feein any case. In a possible embodiment, the call is then also cleareddown.

The following is thereby achieved:

a) For the normal user (legal user), or, more precisely, for theterminal via which the user is calling the service, further unsuccessfulauthentication processes caused by input errors also remain free ofcharge up to a certain number, if, within the same call, a successfulauthentication does finally take place.

b) In contrast, in case of misuse the attempted abusive use becomessubject to fee, due to the large number of unsuccessful authenticationattempts. The misuse thereby becomes economically unworthwhile.

The method explained can of course also be constructed in such a waythat the cancellable charge is calculated according to the number ofunsuccessful authentication processes, rather than by time units.

If the cancellable fee assessment takes place according to time unitsand the number of attempts, a further construction can be that acancellable charge according to time units takes place already at thebeginning of the call, in contrast to which the cancellable chargeaccording to the number of attempts is not activated until after adetermined number of unsuccessful authentication processes.

If both methods, i.e. the chance-controlled charge and the cancellablecharge, are combined, the probability of charge in case of input errorsis reduced still further for the normal user. The user can then reckonwith a chance probability of charge of only e.g. 1:20 in case of inputerror, if he does not succeed in carrying out a subsequent successfulauthentication within the same call.

Unfortunately, in the case of misuse failed attempts are then alsocharged a fee only with the same chance probability. However, this issufficient if the existing statistical degree of security is relativelyhigh due to a greater number of digits for user identification and/orPIN, so that in the case of misuse a very large number of authenticationattempts is necessary.

The invention is not limited to the particular details of the method andapparatus depicted and other modifications and applications arecontemplated. Certain other changes may be made in the above describedmethod and apparatus without departing from the true spirit and scope ofthe invention herein involved. It is intended, therefore, that thesubject matter in the above depiction shall be interpreted asillustrative and not in a limiting sense.

What is claimed is:
 1. A method for impeding misuse in communication services, in a communication network, comprising the steps of:inputting at a network terminal user-specific authentication data for calling a communication service; authenticating the data using the communication network; effecting a chance-controlled charge for the network terminal used to call the communication service, before a service user at the network terminal can determine that there has been an unsuccessful authentication.
 2. A service controlling system in a network, comprising:the network having at least a communication service, a network terminal and an exchange; user-specific authentication data that is submitted by a user at the network terminal in association with a call to the service and that is communicated to the service controlling system of the called service via the exchange; the service having an authentication checker for checking the data and the exchange having a fee assessor for charging a fee to the user; given a call to the communication service by the user, authentication is carried out by checking the authentication data indicated by the user and, given successful authentication, the user is given access to the communication service; the service controlling system invoking a charge according to a predetermined probability for the network terminal used to carry out the call, before the user can determine that there has been an unsuccessful authentication. 